Rotella 5w-40 / 28 hrs / Yamaha F115 outboard

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May 17, 2012
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Marietta, GA
First season using the T6 5w-40 in my outboard and wanted to have a sample analyzed. Had been running Yamalube 10w-30. I got a lot of negative replies on a couple of boating forums when I first asked if anyone was using a HDEO in an outboard. Everyone said that I should use a FC-W rated oil. ANYWAY.... Here are the results..... Shell Rotella T6 5w-40 28 hrs on oil (1 season) 198 hrs on engine aluminum 1 chromium 0 iron 5 copper 1 lead 0 tin 0 moly 69 nickel 0 manganese 1 silver 0 titanium 0 potassium 2 boron 50 silicon 12 sodium 4 calcium 822 magnesium 1064 phosphorus 1032 zinc 1199 barium 0 SUS viscosity @ 210* F 60.3 cST viscosity @ 100* C 10.31 flash point 385 fuel <0.5 antifreeze 0 water 0 insoluble 0.2 Any comments? Thanks.
 
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It sheared to a 30 grade but there's hardly any wear. The drop in grade does not appear to be fuel-related. If the engine calls for 10w-30 I think you made a wise choice. The hours are probably only 1-2,000 miles in an automobile, right?
 

TOMJ

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I often wondered how hours on a engine related to miles. I thought that only 28 hrs on the oil would be fairly low mileage. I did some research concerning HDEO oils vs FC-W oils as I have a VERY bad case of OCD concerning such things and the Rotella T6 seemed like a good choice compared to the over priced marine oil and it's available at Wal-Mart so it's more convenient to purchase. I have been running the T6 in my motorcycle for several years and it's nice to be able to use the same oil (and filter) 1n both. Last year I switched to the T6 in my Sea Doo as well and will send a sample to Blackstone when I change the oil next fall. So that's all three of my toys running the T6 now. Poor sea Doo only got used less than 10 hours this past season so I figured I'd change the oil every two years.
 

TOMJ

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The engine is on a pontoon boat so it doesn't get operated at WOT very often, mainly cruising along at 3,000-4,500 RPM. And I swear it seems to run better with the Rotella than with the Yamalube. The engine seems quieter and on the few occasions that I do run WOT it sounds so sweet.
 
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I guess your boating forum friends were wrong, for sure. This is excellent results. The oil is readily available, affordable, and in this case, appears to be perfect for what you need.
 

TOMJ

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That's what I had read in my research before deciding to use the T6. All I got from the boating forums was "why would you use a diesel oil in your outboard" and "you need to use a FC-W rated oil". The T6 seemed like a good choice for the outboard motor as Yamaha states in the owner's manual that an API SL rated oil anywhere between a 5w-30 & 20w-50 can be used if the recommended oil is not available.
 
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CT8

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Originally Posted By: TOMJ
That's what I had read in my research before deciding to use the T6. All I got from the boating forums was "why would you use a diesel oil in your outboard" and "you need to use a FC-W rated oil". The T6 seemed like a good choice for the outboard motor as Yamaha states in the owner's manual that an API SL rated oil anywhere between a 5w-30 & 20w-50 can be used if the recommended oil is not available.
Most people read on a subject they know nothing about then not knowing whether the write up is fact or fiction. Then like the experts they think they are regurgitate their newly learned facts. 5W - 40 have more viscosity improver than a 15w -40 petro oil.
 

TOMJ

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Originally Posted By: webfors
Excellent results! With that level of shearing I would not run a 30 weight.
No more Yamalube 10w-30 for me, I'll be sticking with the T6
 
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